I think it's likely that what you call slop is more often than not "good enough".
One thing a lot of developers aim for in their code, beyond "it does what it is meant to", is something along the lines of elegance (that's my word for it, there may be a better one).
With AI generated code there is no time for elegance. It will happily recreate the same function in several different places for no reason. And that really doesn't matter anymore.
Said another way: AI generated code doesn't chase perfection. It just chases good enough.
But it's not good enough. We can see this all over industry where even M$ is producing software so bad even calculator is electron app. Slow, poor quality and for any engineer below acceptable
Producing things that aren't good enough has never stopped companies from becoming multibillion dollar entities. I've been waiting for 40 years for good software to take over the market... and I'm still waiting.
>> It will happily recreate the same function in several different places for no reason
So do many developers. I've lost count how many times a code review had to be rejected or cleaned up because of copy and pasted code and I'm going to admit, sometimes it's just quicker to duplicate a little code and leave a comment for 'next time'.. we've all done it.
.. like this one time I had a PR and the developer created on loooong linear method, couldn't figure out how to share between targets and copied and pasted the same bad code somewhere else. Somehow it got through and when asked why this was on production the answer was 'it worked'.
>> no time for elegance
This happens, your experience in is generally your quality out. But that doesn't necessarily mean there's going to be elegance. I've worked at major product driven companies where elegance took a back seat to getting release out the door.